Ontario is on the cusp of helping oil-sands emissions explode. Shell Canada wants permits to be granted by the end of this year for a new refinery in Sarnia to process oil from its oil-sands mines in Alberta for use in gas tanks across the GTA.

The company will be submitting its environmental assessment in June, but the governments of Canada and Ontario are already being pressed to make crucial decisions about the refinery.

Ontarians correctly point fingers at Alberta's dirty oil, but our own hands are hardly clean since Sarnia is already home to oil-sands pioneer Suncor. The pollution hotspot is sometimes called "Chemical Valley," and the local Aamjiwnaang First Nation believes this contributes to its skewed birth ratio, with newborn girls outnumbering boys by two to one.

What makes this proposed Shell refinery different, though, is today's understanding of the global warming crisis. Producing a barrel of oil from the oil sands results in three times as much greenhouse gas pollution as regular oil. Decisions that we make today about our energy supply will determine whether our children inherit a global warming catastrophe. "We need the oil" simply isn't a good enough answer.

The situation is more scandalous when you consider that there is much more Shell and other oil-sands companies can do to clean up their act. The industry says it knows how to capture and store its carbon, but it's stalling by asking taxpayers to pick up the tab to do this despite earning record profits. The industry also knows how to clean up its toxic mess, from the giant oil-sands tailings ponds you can now see from space to pollution from refineries, but governments are not requiring this to happen.

There's little debate the oil sands prevent Ontario and the rest of Canada from tackling global warming. The weak federal "intensity" system to reduce emissions per unit of production while letting overall emissions rise was tailor-made to permit rapid expansion of oil-sands development.

This means that big polluters all across Canada are not subject to hard caps on emissions unless provincial governments enact better provincial emissions laws. B.C. is moving in this direction, and Ontario, Quebec and Manitoba are thinking about it.

As long as Ottawa remains missing in action, though, the gains made by progressive provincial action will continue to be wiped out by growing oil-sands emissions. And, with each new oil-sands mine, pipeline or refinery approved by federal and provincial governments across Canada, we all become more complicit in saying one thing – that we want to reduce emissions – while doing another.

If we don't draw a line in the oil sands now, when will we? If not in Sarnia, then where? The federal government's climate plan allows for the tripling of oil-sands emissions over the next decade, and our saying "yes" to Shell means that we are okay with that.

In fact, we are well past the time when it is politically courageous for governments to refuse permits until companies respect the environment. Voters are waiting for politicians to catch up to them – indeed a recent survey by McAllister Opinion Research found 79 per cent of Canadians want oil-sands emissions capped and reduced instead of allowing them to rise.

But we need to take a stand to make it happen. Ontario should tell the federal government it will not approve new oil-sands infrastructure like the proposed refinery in Sarnia until the "intensity" system is replaced with hard caps and emissions are required to drop as of today. Anything else keeps us hostage to the oil sands.

Gillian McEachern is senior campaigner, boreal and climate, for ForestEthics. Matt Price is a project manager for Environmental Defence